Rotary abrading tool



Feb. 22, 1949. v E, w, HALL 2,462,741

ROTARY ABRADING TOOL 5 Sheets-Sheet 1 Filed March 6, 1946 inve hi0 2E5225 714 W Hall.

.Feb. 22, 1949. Ev w. HALL ROTARY ABRADING TOOL 3 Sheets-Sheet 2 FiledMarch 6, 1946 Feb. 22, 1949. EQW. HALL 2,462,741

ROTARY ABRADING TOOL Filed March 6, 1946 3 Sheets-Sheet 3 l l I 1 l 1 Il 19 4* I| I l i 7 l I I l l I 1 121120341502" Elisha WHaZZ, vfit im Mn.

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Patented Feb. 22, 1949 UNITED STATES PATENT OFFICE 2,462,741 ROTARYABRADING TOOIi Elisha W. Hall, Scituate, Mass.

Application March 6, 1946, Serial No. 652,253

7 Claims.

This invention relates to rotary abrading tools of the class in whichthe abrading material (either a continuous ring or a plurality ofdistinct abrading elements) is mounted on a hub which is constructed andarranged to permit removal of the abrading material when too greatlyworn for further use, and replacement by other abrading material. Theinvention is more particularly concerned with a novel and improvedconstruction ensuring safe confinement and retention of the abradingmaterial when in use, while permitting rapid and convenient disassemblywhen the abrading material is to be replaced. The invention is alsoconcerned with a novel relative arrangement of the abrading material andthe hub to give to the latter a conformation which will produce an axialwiping action to minimize grooving of the work. These and other featureswill appear during the course of the following description when taken inconnection with certain embodiments of the invention, while its scopewill be pointed out more particularly in the appended claims.

In the drawings:

Fig. l is an elevation of a rotary abrading wheel embodying theinvention;

Fig. 2 is a sectional view on an enlarged scale on line 22 of Fig. 1;

Fig. 3 is a sectional View similar to Fig. 2, showing a modification;

Fig. 4 is a sectional View on line 4-4 of Fig. 1;

Fig. 5 is a modification of the arrangement shown in Fig. 4;

Fig. 6 is an elevation of one of the abrading elements removed from thehub and unfolded to display its form;

Fig. 7 is an edgewise View illustrating one manner of building up therequired thickness of abrading material from a strip of cloth ofindefinite length;

Fig. 8 is an elevation of a modified abrading element; and

Fig. 9 is a sectional view on line 9-9 of Fig. 8.

Referring to the drawings and to the embodiments of the inventionillustrated therein as examples, and having reference at first to Fig.2, there is shown a rotary abrading wheel comprising a hub i6, and amass of abrading material I2, attached to the hub in a novel mannerpresently to be described. In the present example, this mass of abradingmaterial, instead of being in the nature of a continuous ring which itmight well be, is in the nature of an annular series of distinct bodiesor elements [4, separately attached to the hub.

While the abrading material might be a single thickness of textilematerial of considerable thickness, and there are such materialsavailable commercially, in the present example it is convenient toemploy bias-cut, cotton cloth in the form of a strip l6 of indefinitelength built up REiSSiiED to the required thickness as by being firstwound in a drum arid then flattened (see Fig. 7) to provide aconsiderable number of plies (sixteen, for example) with folds i3 ateach end of the multiply mass. This mass may be shaped as desired, andin the present example its corners are angularly chamfered as at 28, andnotched as at 22, and perforated as at 24 to reduce the bulk at thesepoints.

To prepare these multi-ply abrading elements Hi for attachment to thehub H3, each is provided with a plurality of slots 26, for example twopairs of such slots, preferably reinforced as by patches 28, alsoslotted in like manner and stitched in place. These patches orreinforcements may be, for example, relatively heavy, strong materialsuch as canvas or duck which imparts great strength to the abradingmaterial at its points of attachment to the hub Ill. It is desirable,though not necessary, to unite the cloth plies (see Fig. 6) with rows ofstitches 29 which in this example are in lines which (see Fig. 1) aredisposed radially. These stitches prevent separation of the plies andlend firmness to the abrading element.

To prepare the described abrading element for attachment to a hub suchas the one presently to be described, according to the embodiment nowunder consideration, the mvl'ti-ply mass is folded along a median line33-41: (see Fig. 6) which bisects the notches 22 and the aperture 2 iand lies midway between slots 26 of each pair, with the result that theslots of each pair then coincide, the notches 22 become chamfers, andthe aperture 2i becomes a notch in the now folded mass. According to themodification shown in Fig. 8, instead of employing a fold such as thatjust described, a narrower strip is employed, wound and flattened asbefore, but having only two slots 25'. In this form there is areinforcement 28' folded over the adjacent edges of the plies so as toembrace them, and stitched in place as before.

To make the material about the slots compact, and to reduce frictionbetween the fabric and the hub ID, that local area about the slots isnext treated with suitable material such as paraflin 3!], applied hot,or suitable plastic compound such as urea formaldehyde, a cold settingresin glue which will penetrate the fibers, and when subjected topressure by squeezing in a press, the material is compacted and reducedin bulk so as to be introduced readily into a small space in the hub ID.The binder also tends to maintain the folded condition of the abradingelement.

Several such abrading elements may be attached to an appropriate hubsuch as that now to be described, and one or more, usually several, ofthese hubs placed coaxially on an arbor. One hub which serves thepurpose particularly well comprises two sets of holders such as lugs 32on plates 34 (see Fig. 2), the lugs on one plate being ease next lug 32'on the other plate is introduced through the other pair of slots 25,a'peculiar and desirable formation of the abrading element results. Onesuch formation is illustrated in Fig. 4 and is characterized by areverse curve or- 8 curve, while another formation is illustrated inFig. 5, and is characterized by a U curve; formation has advantages wheninuse, particularly a wiping action in an axial direction, tending Eachto minimize grooving of the work. Eachofithese formations is possible bythe use of the staggered arrangement of the lugs. To maintain thisstagcuredv together for relative non-rotation, as, for

example, by securing them by screws 35 to acentral disk 38 which may bewood, laminated or otherwise.

In the present embodiment, the lugs 32 of one plate 34 have their freeends extending in an opposite direction to the lugs of the other plate.It is preferred not to rely upon the lugs 32 alone to prevent accidentaldetachment of the abrading elements from the hub, even though thestaggered arrangement and the folds of the abrading elements tend toprevent such detachment. Instead of relying wholly upon thesearrangements, I prefer to employ means positively to lock the abradingelements in place on the lugs. such means will now be described,reference being had to Fig. 2. This particular retaining means involvessimply associating with each plate at another plate 55 having a marginalportion 42 which overlies the several abrading elements. When severalassemblies such as the one shown in Fig. 2 are placed coaxially on anarbor and secured thereon by the usual clamping plates and nut threadedupon the arbor, the retaining plates prevent accidental disengagement ofthe abrading elements from the lugs. However, be-

fore the assembly is placed upon the arbor, it.

may be desirable to hold the assembly together,

temporarily, as by a bolt d4 having'a nut 46.

The retaining plate ii! may take the form shown in Fig. 2 with acircumferential flange-or lip '38 and with an offset 5i)which-constitutes a spacer preventing the margin 62 from undulyrestraining the abrading elements M, or it may take the form shown inFig. 3 in which there is a plate 42A which has no oifset but insteaditheplatet iAhas an oifset 59A which constitutes aspacer. Some sort ofspacer is desirable though perhaps not necessary, as without the spacerthe retaining plate would then be unrestrained. and would clamp theabrading elements firmly to the plates having the lugs.

Having thus described these embodiments of the invention, what Iclaimis:

i. In a rotary abrading tool, the'combination of a hubhaving two sets oflugs, the lugsofone set alternatingwith the lugsof the other set, andthe lugs of one set having free ends extend- .ing in a directionopposite to those of the-*other;

set, and a. circumferential mass of abrading material having alternateopenings receiving alternate lugs.

2. In a rotary abrading tool, the combination of two circumferentialsets ofholders, the holders of one set alternatingwith and beingdisplaced axially with relation to the holders of the other. set, eachset having free ends extending in-a direction opposite to those of theother'set, and abrading material heldby the holders of both '15 geredarrangement, the plates 34 are suitably se-' One lengthwise of the axisof rotation, and each being held inpartby the next succeeding holder ofthe other set.

4. In a rotary abrading tool, the combination of two circumferentialsets of holders, .theholders of one set being displaced axially withrelation to and alternating. with the holders of the other set, and acircumferential setof abrading elements, each held in part by a holderof one set .having a curved offset formation extending lengthwise. ofthe axis of rotation, and'each being held in part by the next succeedingholder of the other set.

5. In. arotary abrading tool, the combination of two circumferentialsets of holders, the holders of one setbeing displaced axially withrelation to the holders of the other set, and a circumferwith relationto the holders of the second set, and

a set of abrading elements each having two openings, one openingreceiving a lug of one set and the other opening receiving a lug of theother set, andeach abrading element having a portion ofi setintermediate its openings and displaced lengthwise of the axis.

'Z. In a rotary abrading, tool, the combination of a hub having two setsof lugs extending lengthwise of the axis of rotation, the lugs of oneset being displaced axially with relation to and stagger'ed withrelation tothe holders of'the second set, one set having free endsextending in the opposite direction to -those of the other set, and aset of abrading elements, each having two openings, one receiving alugof one set and extending thencelengthwise of the axis of rotation toand receiving a lugo-f the otherset.

ELISHA .W. HALL.

REFERENCES CITED The following references are of record in the file ofthis pate-n UNITED STATES PATENTS Number Name Date Re...19,894 Myers: etal Mar. 17, 1936 269,688. Levctt Dec: 26, 188-2 872,966 Painter Dec. 3,1907. 968,431v Stevens Aug; 23, 1910 1,141,143 Radlein et al. June-1,1915' 2,017,925 Siefen Oct. 22, 1935 2,039,952 Springer Nova 17, 19362,169,403- liicksfln'- May 30,1939 2,226 624 MacFarl-and 'et ai. Dec.31-, 1-940 2,226,625 MacFarlandet a1. Dec, 31', 1940 2,280,399- Garling-Apr. 21, 1942 2,355,667 Melton'et a-l. Aug. 15, 19.44

Disclaimer 2,4627 41.Elz'skw W. H all, Scituate, Mass. ROTARY ABRADINGTOOL. Patent dated Feb. 22, 1949. Disclaimer filed J an. 22, 1951, bythe inventor. Hereby enters this disclaimer to claim 5 of said patent.

[Oficz'al Gazette Febmmg 20, 1951.]

